Small crack forming on dash, How to stop??
 

Hey guys,

I have a small crack forming near the defroster vent on the top of my dash on my 85 carrera. Do any of you guys know how I can stop it from getting bigger? I was wondering if there is some short of glue to use?? Let me know what you think...

Thanks......Joey

Joey: When plexiglas splits on helicopters, a small hole is drilled at the end of the crack. Often that will prevent it from spreading. You might try something similar.

Good luck.

Don't take my word for it, but I've heard that it helps to drill a small hole on both sides of the crack (and afterwards fill the crack with some sort of silicone)

Hi 3.2 Carrera
I to have same crack forming, I tryed the small hole as well but it still keeps cracking. I have used some glue but that is not working. Hope some one will come up with an answer.
Cheers Steve.

Thanks guys i am going to try and drill a small hole....

i am hoping that my drill will fit in that position, its kind of tight, with the windshield being their and the dash,

so I just drill a small hole at the end of the crack, its a very small crack and hopefully it will not get bigger, that makes sense you stop it from forming...and getting longer..will do it 2marrow after waxing the car:)

Drilling the holes releases the stress that is causing the crack to form in the first place. However, based on my understanding, the hole has to be large enough to accomplish the stress reduction. My suggestion would be to get a professional upholstery shop to give you a recommendation. Also, if you plan on keeping the car for many years to come, consider buying a used (or new) dash and storing it for use later since the prices aren't as crazy as they are for the early dashes.

What I would like to know is why you think that crack started in the first place? Is your dash drying up? Is the car in the sun a lot? I've seen a lot of early cars with almost perfect dashes so I don't think age is the only contributing factor.

Good luck!

You must seal the car in a vacuum packed glass dome, with
the outside temperature steadily rising at the rate of .0001
degree F. each day. The dash will not crack.
Otherwise, get used to it....it's a Porsche. They all crack
sooner or later.

The suggestions given may work, but the real culprit is heat, UV, and aging vinyl. With the cracking localized and small, release of tension may help and an upholestry shop may be able to repair it, but in the long run, protecting the dash from the big three causes is the only sure prevention, and that's close to impossible. A dash cover helps, as does covering the car when parked outside. Keep the dash clean and "moist" with a good quality vinyl dressing. Try not to let interior temps. rise too high when parked. Watch for cracks by the speaker and especially by the curve just above the clock--that's where it gets ugly. The PO on my car had one of those ABS covers on the dash--not glued down, but just to protect it. Seemed to work well as the only crack was where yours is, and the car is a 75!

It helps to buy reflective heat shields im sure. If not then try to park in the shade.

I've always drilled a small hole to stop cracks from propagating. But if the crack is too close to the windshield for a drill, heat the shaft end of a small drill bit, or grind the shaft to a point then heat with a torch and 'burn' the hole in. That's worked for me in the past also. Be careful to use only enough heat to melt thru the plastic. Too much heat causes a 'lip' of melted plastic around the hole.

They work great in summer sun.

I never leave the dash uncovered while parked. UV is a mf.

Subscribed...with a small crack......on my dash.

No crack yet ('86 Carrera).

What do you guys recommend to protect/treat the vinyl?

Mine's a little faded (almost 'whiteish' in parts).

I like the idea if heating the end of a drill bit and poking a hole into the dash. I think that i am going to try that. Thanks for the advise guys!!! Living in socal, A sun shield is a MUST!!!!

+1

This works well in virtually all materials - metal, plastic, etc. I actually just did it a couple of weeks ago in the bumper of my Mercedes, which had a very small crack in the plastic. Stopped the propagation, now I just filled the small hole with spot putty and put a dab of touch-up paint on it. You can't tell it's there unless you're looking for it.

I've seen this technique used on aircraft a lot.

So, any progress on your repair?

A new dash would take care of that nasty ol'e crack. I'm trying to repair 4 in my 76'. Using the permatex kit.. will let you know how it works.. Im still carefully filling all the cracks with the filler adhesive stuff.. one recommendation.. get one of those medical type needles to inject it.. it makes a real mess and sets up super fast when you get it on the dash.. I wish I had one.. might try and get one tomorrow..

If this doesn't work I will look at a cover because early Dash's are just sill ass money.

If I were you I would inject some epoxy into that crack.. if you do not the edges will start to pop up.. then you will have to cut them with a razor to level them out.. do it now before it starts to happen.. The drill might stop the crack.. but I really doubt it.. your dash is brittle.. end of story.. it will start up again from vibration..

Someone ought to come up with a material that you lay on and heat up that recovers any dash.. that person would be a millionaire I bet.. wishing I was a chemist about now.

I keep the crack area regularly saturated with protectent (not ArmorAll). My theory is if the foam is full of liquidy stuff, it won't continue to dry out and keep cracking. Only a temp solution until dash replacement.

A while back I owned a 1974 Carrera targa. I always had the top off and I had a couple of places on the dash where cracks were beginning to form. I had heard about the hole drilling deal so I decided to give it a shot.

The cracks were in open spots so I used an offset drill and drilled holes big enough to encompass the crack lines. Then when I was deciding how to fill the holes I noticed how evenly spaced they were. So I got out my collection of little (and not so little) black hole plugs and found the proper size and they pushed into the holes like a glove!

I actually drilled one extra hole to make a concentric pattern of the plugs on the dash. Yeah, I know it sounds dumb.....but it worked for me!!

The plasticizer in the dash evaporates over time. This means the dash looses volume - shrinks. Heat and UV speed up this process, but time also does contribute. I have seen dashes in old cars (think GM) that were an inch shorter across than new. Sometimes dashes and steering wheels even get a film of plasticizer sweat on them when they sit in the sun. Here is a cool article on this subject: http://www.pslc.ws/mactest/work/dash.htm

I wouldn't worry about it too much. Let it go. You won't keep it from cracking. Put a new dash in the future when it gets too bad. Then the clock starts new and it will be 20 years before it cracks again. My new dash in the SC was a new Porsche part and I actually would bet it lasts longer than the original, as today's materials are definitely better.

George